Chicago’s Trump Tower has become one of the nation’s biggest hotspots for protests against President Donald Trump — and on Friday, seven of those protesters got arrested for doing just that.

According to Chicagoist, seven protesters affiliated with Greenpeace were arrested outside of Trump Tower after putting up a banner on the south side of the tower, facing the Chicago River. It was easily viewed from the river’s harbor.

The “resist, defend” banner went up at about 2 p.m. and reportedly hung for around 30 minutes before it was taken down.